DOCSLIB.ORG

Department of Physics Stanford University, Stanford, California 94305

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Department of Physics Stanford University, Stanford, California 94305 131 BARYON Q-BALLS: A NEW FORM OF MATTER? STEPHEN B. SELIPSKY Department of Physics Stanford University, Stanford, California 94305 Abstract Hadronic effective field theories describing ordinary nuclei also contain ·Q-Ba.11 solu­ tions which can describe a new state of matter, "baryon matter" . Baryon matter is stable in very small chunks as well as in stellar-sized objects, since it is held together by the strong force instead of just gravity. Larger chunks, "Q-Stars" , in which gravity is impor­ A tant, model neutron stars. wide variety of Q-Star models, a.II consistent with known nuclear physics, allow compact objects to have masses much larger, or rotation periods much shorter, than is conventionally believed possible. Smaller chunks of nuclear density baryon matter could also be astrophysically important components of the universe, a.nd at late times would have many properties similar to those of strange matter chunks. 132 1. Introduction There are many surprising possibilities lurking in the non- perturbative sector of field theories. Here we add to the body of work on this topic, presenting the possibility of a new state of matter which a.rises from the discovery of solutions to effective field theo­ ries describing among other things ordinary nuclei. Effective field theories of interacting baryons and mesons ha.ve successfully reproduced measured properties of nuclei a.s wella.s 1 6 results of scattering experiments -3). We have found4- ) non-topological classical solu­ tions to such theories: fermion Q-Balls, or Q-Sta.rs in the ca.se where their self-gravity is important and gravitational effects are included. Q here stands for the conserved charge (baryon number) which stabilizes the matter against decay. The properties of such a state of baryon matter can be different from and essentially independent of the characteristics of ordinary nuclei studied in the laboratory. In particular, neutron stars may have a large binding energy per nucleon, hundreds of MeV, due mainly to nuclear forces, and may be 7 8 more massive or able to rotate fa.st.er than is suggested by currently accepted limits. ' ) 1 In addition, chunks of baryon matter, varying in size from 10- 2cm to several kilometers, may also exist. Structural characteristics are fairly insensitive to the effective field theory used; classes of theories give the same equation of state. 2. Constructing Solutions There is a simple graphical method for finding large baryon-number solutions. Con­ sider a. Lagrangian for a baryon 1jJ intera.cting with a. sca.la.r a.nd vector field: (2.1) 1 It is a good a.pproxima.tion to neglect the dynamics of the vector field ), and fora many­ fermion system we can make the Thomas-Fermi approximation (dm/dr � m2) to get a Fe rmi sea of baryons described by a constant chemical potential EF and a Fermi momen­ 6 tum kF slowly varying in space. The identity gives the cla.ssica.l (i}ij;) = -(8Pv, /8m) ) 133 equation of motion (2.2) where P.p is the pressure of the baryons. This is equivalent to Newton's ma for a. F = · mechanical 'particle' a.t 'position' a a.t 'time' r moving in a potential Veff = P.p - U, with 'friction' from the (2/r)&a/&r term negligible for large r. The Q-Ball solution occurs when a rolls between degenrra.t.r maxima of V.Jf, where one of the maxima is the vacuum and the height. of I.he other is tuned by varying The Ep. a fieldstarts at a value a inside at r = 0, close to the top of t he first hill, and stays near I.hat value out to a. large radius (since the I.op of the hill is flat) before quickly rolling to the vacuum. The large baryon number Q-Ba.ll thus has a flat interior, a radius which is a free para.meter, and a thin surface (of ordrr the scalar Compton wavelength). The density is determined by algebraic equations for and ainsideo requiring degenerate maxima.: Ep Ve ff = 0 and &V,JJ/&a = 0. Q-Ba.11 must still have total energy E QmN in order to A < be bound. Further details can be found in Refs. 6 and 9. 3. Application We can apply this construction quite generally, for instance to Wa.lecka's Quantum 1 Hadro-Dynamics ), in which the proton and neutron a.re fermion fields 1/'i whose effective mass is m(a) = g,a, with the free-particle g8a0. The scalar field has a quadratic mN = potential U = m;(a - a0 )2, and the vector field is the w particle. This theory's large ! baryon number Q-Ball corresponds to infinite symmetric nuclear matter when N = Z. The small baryon number solutions (nuclei) depend on the friction term in eq. (2.2); the rolling starts above P.p - U = 0 and friction brings a to rest at the vacuum value where m = mN. Fig. 1 translates the Walecka. solutions into this framework. Infinite nuclear matter is desta.bilizrd by Coulomb forces. In fact, neutrons, protons, and electrons coexist in ,8-decay equilibrium, allowing local charge neutrality: kp,1, = kF,e 134 ->e.... •ca .... , / ' . · 0.2 , ' /·�- ··.�l ' �� . ' u. ·. · b . � ' ... " 01 · ."::::�' \ I \ ' I ' ' I � ' 2 I r., \ Q�� 0.0 -0.1 a.• o.• o.• -0.2'1 0.25 0.5 0.715 m/m• m/m. 1. Figure Graphical representation of Q-Balls in a nuclear theory. U(u) (dots) is the scalar field potential, is the baryon pressure, and U is the effective potential that 'rolls' in, P.p P.µ - u starting at r = 0 (marked by crosses). Figure 2. Potentials U (solid lines) given in Refs. 1 and 2. and E:F n E:F E:F e With a baryon pressure function reflecting this, a large baryon , ,p , · = + number Q-Ba.11 does not exist in Wa.lecka.'s theory, so strong gravity for stellar sized objects is the only possibility. However we a.re still free to choose other potentials. In an effective field theorythe potential and the coupling m(a) a.re in genera.I nonrenormaliza.ble, subject only to the symmetry of the underlying theory, and should either be fit fromexperiment (a la Walecka) or derived from the underlying theory (QCD). Then m and U have quantum corrections included in their definitions. Bogut.a., Strocker, and others have found many models with renorma.liza.hle potentia.ls which reproduce known hulk properties of nuclear matter\ Fig. 2 shows these and Wa.lecka.'s potentials; the region 'a.-b-c-d'is the only pa.rt relevant for nuclear data, and U is not constrained elsewhere, allowing infinitely many altered potentials (e.g. dotted lines) that do give la.rge baryon number Q-Balls. Only the (currently unmeasurable) point determines Q-Ball hulk properties, and the rest of U ' f ' affects only the thin surface. Iu this way we can have stable macroscopic chunks of high density baryon matter, of any size above where surface dfPcts become important. Qbulk To fix point 'f' and the properties of nn1tron stars, experiments on baryon matter chunks would be necessary. 135 The simple 'chiral' Q-Ball case in which the bulk-phase nucleon mass m(ainside) = 0, has features genetic to more complicated models (which have also been solved). The equation of state9) for a chiral Q-Star (neglecting the electron mass and neutron-proton mass difference) depends only on the vector repulsion strength and Uo = U (a inside): 3/0 E-3P-4Uo + o:v (E-P-2Uo) -=0, (3.1) 2 112 7r to the strong forces, so charge with /mv ) 3 / . Only the nucleons couple O:v = (gv separation results in the surface. Structure calculations may neglect these details since the surface width is about 10-20 times sma.ller than the stellar radius, but the electrostatic gap means that small Q-Balls will not absorb ordinary matter and Q-Stars can support a crust of degenerate ordinary matter below neutron drip densities. Since Q-Balls are a bulk phase with an equation of state\ gravity can be included simply by integrating the Oppenheimer-Volkoffequations. On dimensional grounds, when GM/R 1 a Q-Star has radius R � mvw0'2 � 100 km and mass M � m;1a02 10 M0, � � where IOOMeV is the vacuum val ue of Integrating the Oppenheimer-Volkolf a0 � a. equations for eq. (3.1) gives the solid lines in Fig. 3. We also show for comparison (dashed lines) two neutron sta.r models (pion condensation and Walecka's) which are respectively among the least stiff a.nd most stiff of conventional neutron star models. In conventional models the stellar radius decreases as the mass and baryon number increase, while Q-Balls have M and Q giving the generic curlique. ex R3, Both stellar radius a.nd mass increase as the unknown Uo decreases, allowing a large upper limit for the neutron star mass if Uo is small. However eq. (3.1) is only valid at densities high enough for the nuclear interactions to domina.te. There seem to be no experimental constraints on the equation of st.ate of a large nvmber of baryons above white dwarf densities 0 0gm cm3 which we will take as the lowest permissible ( I / ), U0 < 1 val ue. Using (3.1) down to density Uo evades the theoretical Rhoades-Ruffini limit, 3.2M8, which assumes some conventiona.l <"qna.tion of st.ate below a density ta.ken to be about [0 136 x trI ] 10 20 30 •o R(km) 3.
Load more

Recommended publications
  • 1 Kepler's Third
    Astronomy 114 { Summary of Important Concepts #1 1 1 Kepler's Third Law Kepler discovered that the size of a planet's orbit (the semi-major axis of the ellipse) is simply related to sidereal period of the orbit. If the size of the orbit (a) is expressed in astronomical units (1 AU equals the average distance between the Earth and Sun) and the period (P) is measured in years, then Kepler's Third Law says P 2 = a3: After applying Newton's Laws of Motion and Newton's Law of Gravity we find that Kepler's Third Law takes a more general form: 4π2 P 2 = a3 "G(m1 + m2)# in MKS units where m1 and m2 are the masses of the two bodies. Let's assume that one body, m1 say, is always much larger than the other one. Then m1 + m2 is nearly equal to m1. We can then use our technique of dividing two instances of this equation derive a general form of Kepler's Third Law: MP 2 = a3 where P is in Earth years, a is in AU and M is the mass of the central object in units of the mass of the Sun. So M = 1 whenever we talk about planets orbiting the Sun. Examples: Q: The Earth orbits the Sun at a distance of 1AU with a period of 1 year. 12 = 13. Suppose a new asteroid is discovered which orbits the Sun at a distance of 9AU. How long does it take this object to orbit the Sun? A: MP 2 = a3 (1)(P 2) = 93 P 2 = 729 P = p729 = 27 years Astronomy 114 { Summary of Important Concepts #1 2 2 Newton's Law of Gravitation Any two objects, no matter how small, attract one another gravitationally.
    [Show full text]
  • Abbreviated Curriculum Vitae
    Abbreviated Curriculum Vitae GRANT J. MATHEWS February 20, 2012 ADDRESS Department of Physics Center for Astrophysics University of Notre Dame Notre Dame, IN 46556 email: [email protected] off: (574) 631-6919 , FAX: (574) 631-5952 BIRTHDATE: October 14, 1950 PRESENT POSITION: • Nov. 1994 - Present Professor Department of Physics University of Notre Dame and • Sept. 2000 - Present Director, Center for Astrophysics at Notre Dame University (CANDU) University of Notre Dame PREVIOUS POSITIONS: • Apr. 1993-Nov. 1994 Senior Scientist Physical Sciences & Space Technologies Di- rectorate Physics Research Program/P-Division University of California, Lawrence Livermore National Laboratory and 1 • Sept. 1992-Nov. 1994 Adjunct Professor of Physics and Astronomy University of California, Davis • Oct. 1986-Apr. 1993 Group Leader for Astrophysics Physics Department/E-Division University of California, Lawrence Livermore National Laboratory • Apr. 1981-Oct. 19886 Physicist Physics Department/E-Division University of Cal- ifornia, Lawrence Livermore National Laboratory • Nov. 1979-Apr. 1981 Senior Research Fellow California Institute of Technology, W. K. Kellogg Radiation Laboratory • Sept. 1977- Nov. 1979 Research Associate University of California, Lawrence Berke- ley Laboratory • May-Sept. 1977 Post-Doctoral Research Associate, University of Maryland EDUCATION: • B.S., June 1972, Michigan State University • Ph.D., May 1977, University of Maryland, College Park, MD Dissertation: Re- flections and Research on: I) The Nucleosynthesis of Light and Heavy Nuclei; II) A Generalized Theory of Odd-A Nuclei; III) A Study of Three Heavy-Ion Systems HONORS: • Research Excellence Award of the Society of the Sigma Xi (1976) • Assoc. Western Univ.-ERDA-Fellowship to Lawrence Berkeley Laboratory (1976) • Visiting Scientist: California Institute of Technology (1981) • Guest Scientist: Max Planck Institute for Astrophysics (1984) • Distinguished Visiting Professor: Univ.
    [Show full text]
  • Observations and Properties of Candidate High Frequency GPS
    Mon. Not. R. Astron. Soc. 000, 1–21 () Printed 30 October 2018 (MN LATEX style file v2.2) Observations and properties of candidate high frequency GPS radio sources in the AT20G survey Paul J. Hancock1,2, Elaine M. Sadler1, Elizabeth K. Mahony1,2, Roberto Ricci3 1Sydney Institute for Astronomy (SIfA), School of Physics, University of Sydney, NSW 2006, Australia 2Australia Telescope National Facility, CSIRO, PO Box 76, Epping, NSW 1710, Australia 3INAF-Istituto di Radioastronomia, Bologna, Via P. Gobetti, 101, 40129 Bologna, Italy ABSTRACT We used the Australia Telescope Compact Array (ATCA) to obtain 40GHz and 95GHz ob- servations of a number of sources that were selected from the Australia Telescope Compact Array 20GHz (AT20G) survey . The aim of the observations was to improve the spectral cov- erage for sources with spectral peaks near 20GHz or inverted (rising) radio spectra between 8.6GHz and 20GHz. We present the radio observations of a sample of 21 such sources along with optical spectra taken from the ANU Siding Spring Observatory 2.3m telescope and the ESO-New Technology Telescope (NTT). We find that as a group the sources show the same level of variability as typical GPS sources, and that of the 21 candidate GPS sources roughly 60% appear to be genuinely young radio galaxies. Three of the 21 sources studied show evi- dence of being restarted radio galaxies. If these numbers are indicative of the larger population of AT20G radio sources then as many as 400 genuine GPS sources could be contained within the AT20G with up to 25% of them being restarted radio galaxies.
    [Show full text]
  • Introduzione Alla Cosmologia Fisica Lezione 14
    Introduzione alla Cosmologia Fisica Lezione 14 Gli oggetti compatti, Supernovae, Stelle di Neutroni e Pulsar, Buchi Neri. Giorgio G.C. Palumbo Università degli Studi di Bologna Dipartimento di Astronomia Giovane Pulsar in G11.2-0.3 La Crab Pulsar: Diagramma P-Pdot NS X emittenti Vicine • NS in raffreddamento • Magnetar di mezza età (decadimento di B) • Accrescimento dall’ ISM Campi Magnetici Frequenza di ciclotrone Ω = eB/mc Ciclotrone da elettroni: ν = 3 Hz B (micro Gauss) 12 Energia = 10 keV (B/10 ) G 13 BQED = 4x10 Gauss Campi Magnetici • Righe di ciclotrone in pulsar in accresciemento • Features in NS vicine brillanti in Raggi-X – Alcune vengono interpretate come ciclotrone da protoni – Features in alcuni casi sono larghe Le quantità osservate sono redshiftate 2 Raggio di Schwarzchild Rs = 2GM/c 2 talvolta anche rg = GM/c ∞ 1/2 T = Ts [1-Rs/R] ∞ ∞ L γ= Lγ [1-Rs/R] ∞ s 1/2 R γ= R / [1-Rs/R] ∞all’infinito e s sulla s uperficie della pulsar La maggioranza delle SN produce NS? Enigmatica Sorgente in Cas A Cosa c’è al centro della SNR 1987A? Kaplan’s thesis: what is in the centers of shells? Masse delle Neutron Stars Neutron Star Masses Raggio (Rotazione) delle NS Oscillazioni coerenti da LMXBs Massimo tasso di Spin 642 Hz: è questo il periodo limite ? • Gli spin delle Stelle di Neutroni non possono essere accelerati (radiazione gravitazionali) • Il periodo limite è fondamentale nell’equazione di stato della materia densa Raggi delle NS: limiti dal periodo di spin Formazione di NS Spin-down and Magnetic Dipole Model • Pulsars are observed to spin w/ periods of ms to Ω=2π/P seconds: α - for non-accreting systems, P increases with .
    [Show full text]
  • Astrophysical Evidence for the Existence of Black Holes 3 Dissipated, Chandrasekhar Was Awarded a Share in the Nobel Prize for This Discovery
    TOPICAL REVIEW Astrophysical evidence for the existence of black holes A Celotti, J C Miller and D W Sciama SISSA, Via Beirut 2-4, 34013 Trieste, Italy. Abstract. Following a short account of the history of the idea of black holes, we present a review of the current status of the search for observational evidence of their existence aimed at an audience of relativists rather than astronomers or astrophysicists. We focus on two different regimes: that of stellar-mass black holes and that of black holes with the masses of galactic nuclei. arXiv:astro-ph/9912186 v1 9 Dec 1999 Date: 16 November 2003 1 2 A Celotti, J C Miller and D W Sciama 1. Introduction In his famous article of 1784, which is seen as being the beginning of the story of black holes, John Michell [1] wrote: If there should really exist in nature any [such] bodies, ... we could have no information from sight; yet, if any other luminous bodies should happen to revolve about them we might still perhaps from the motions of these revolving bodies infer the existence of the central ones with some degree of probability, as this might afford a clue to some of the apparent irregularities of the revolving bodies, which would not be easily explicable on any other hypothesis. There at the very beginning, the theoretically-predicted properties of (Newtonian) black holes were discussed together with a carefully-worded statement about how it might be determined observationally whether such objects do in fact exist. Following Michell’s paper and the subsequent repetition of his arguments by Laplace [2] in his book of 1796, there is a long gap until the present century when, with the coming of general relativity, the theoretical discussion of black holes started anew.
    [Show full text]
  • Black Hole Physics Entering a New Observational Era
    Black hole physics entering a new observational era Eric´ Gourgoulhon Laboratoire Univers et Th´eories (LUTH) CNRS / Observatoire de Paris / Universit´eParis Diderot 92190 Meudon, France [email protected] http://luth.obspm.fr/~luthier/gourgoulhon/ Seminar at Laboratoire de Math´ematiqueset Physique Th´eorique Tours, 29 November 2012 Eric´ Gourgoulhon (LUTH) Black holes physics entering a new observational era FDP, Tours, 29 November 2012 1 / 58 Outline 1 Part 1 What is a black hole ? Overview of the black hole theory The current observational status of black holes The near-future observations of black holes 2 Part 2 Tests of gravitation The Gyoto tool Ray-tracing in numerical spacetimes Eric´ Gourgoulhon (LUTH) Black holes physics entering a new observational era FDP, Tours, 29 November 2012 2 / 58 Part 1 Outline 1 Part 1 What is a black hole ? Overview of the black hole theory The current observational status of black holes The near-future observations of black holes 2 Part 2 Tests of gravitation The Gyoto tool Ray-tracing in numerical spacetimes Eric´ Gourgoulhon (LUTH) Black holes physics entering a new observational era FDP, Tours, 29 November 2012 3 / 58 Part 1 What is a black hole ? Outline 1 Part 1 What is a black hole ? Overview of the black hole theory The current observational status of black holes The near-future observations of black holes 2 Part 2 Tests of gravitation The Gyoto tool Ray-tracing in numerical spacetimes Eric´ Gourgoulhon (LUTH) Black holes physics entering a new observational era FDP, Tours, 29 November 2012 4 / 58 Part 1 What is a black hole ? What is a black hole ? ..
    [Show full text]
  • Drops of Strange Chiral Nucleon Liquid (SNL) & Ordinary Chiral Heavy Nuclear Liquid (NL)
    Liquid Phases in SU3 Chiral Perturbation Theory (SU3 PT ): Drops of Strange Chiral Nucleon Liquid (SNL) & Ordinary Chiral Heavy Nuclear Liquid (NL) Bryan W. Lynn University College London, London WC1E 6BT, UK & Theoretical Physics Division, CERN, Geneva CH-1211 [email protected] Abstract SU3L xSU3R chiral perturbation theory ( SU3PT ) identifies hadrons (rather than quarks and gluons) as the building blocks of strongly interacting matter at low densities and temperatures. It is shown that of nucleons and kaons simultaneously admits two chiral nucleon liquid phases at zero external pressure with well-defined surfaces: 1) ordinary chiral heavy nuclear liquid drops and 2) a new electrically neutral Strange Chiral Nucleon Liquid ( SNL) phase with both microscopic and macroscopic drop sizes. Analysis of chiral nucleon liquids is greatly simplified by an spherical representation and identification of new class of solutions with ˆa 0 . NL vector and axial-vector currents obey all relevant CVC and PCAC equations. are therefore solutions to the semi-classical liquid equations of motion. Axial- vector chiral currents are conserved inside macroscopic drops of SNL, a new form of baryonic matter with zero electric charge density, which is by nature dark. 0 The numerical values of all SU3PT chiral coefficients (to order SB up to linear in strange quark mass mS ) are used to fit scattering experiments and ordinary chiral heavy nuclear liquid drops (identified with the ground state of ordinary even-even spin-zero spherical closed-shell nuclei). Nucleon point coupling exchange terms restore analytic quantum loop power counting and allow neutral to co-exist with chiral heavy nuclear drops in (i.e.
    [Show full text]
  • Astronomy 114 – Summary of Important Concepts #2 1 Stars: Key
    Astronomy 114 – Summary of Important Concepts #2 1 Stars: key concepts This following summarizes important points that I covered in class or are explained in your textbook. Your book will give you additional information about any of these concepts. Use the list a guide to studying. I realize that this is a long list but I’ve tried to make it comprehensive. Exam #2 will only be able to cover some fraction of these, of course. 1. Understand how the Sun produces energy 2. Know what a stellar model is and be able to explain the relationship between pressure, energy generation, energy transport and energy generation 3. Understand how astronomers use the parallaxes of stars to measure their distances 4. Understand how to determine a star’s luminosity from its brightness and distance 5. Know the difference between apparent magnitude and absolute magnitude 6. Be able to explain the relationship between a star’s color and its surface temperature 7. Understand how astronomers use the spectra of stars to reveal their chemical com- positions and surface temperatures 8. Know the sequence of spectral classes of stars 9. Know the relationship among a star’s luminosity, radius, and surface temperature 10. Know what a Hertzsprung-Russell (H-R) diagram is and the main groupings of stars that appear on it 11. Understand how the details of a star’s spectrum reveal what kind of star it is, its luminosity, and its distance 12. Be able to describe visual binary stars and explain how they provide information about stellar masses 13. Know the mass-luminosity relation for main-sequence stars binaries, and eclipsing binaries are 1 14.
    [Show full text]
  • Neil Degrasse Tyson, Answers Our Questions About the 'Cosmos
    RocketSTEMVol. 2 • No. 2 • March 2014 • Issue 6 Neil deGrasse Tyson, answers our questions about the ‘Cosmos’ Spitzer turns 10: Gets a new life An engineer’s work: Boeing’s V-22 Osprey Bigelow envisions a future of inflatable space habitats And much more inside... Photo: Mike Killian NASA launches third generation communications satellite Photo: Mike Killian NASA’s Tracking and Data Relay Satellite L (TDRS-L), the 12th spacecraft in the agency’s TDRS Project, is safely in or- bit after launching January 23 aboard a United Launch Alli- ance Atlas V rocket from Cape Canaveral Air Force Station in Florida. Ground controllers report the satellite – part of a network providing high-data-rate communications to the Internation- al Space Station, Hubble Space Telescope, launch vehicles and a host of other spacecraft – is in good health at the start of a three-month checkout by its manufacturer, Boeing Space and Intelligence Systems of El Segundo, Calif. “TDRS-L and the entire TDRS fleet provide a vital service to America’s space program by supporting missions that range from Earth-observation to deep space discoveries,” said NASA Administrator Charles Bolden. The mission of the TDRS Project, established in 1973, is to support NASA’s space communications network. This net- work provides high data-rate communications. The TDRS fleet began operating during the space shuttle era with the launch of TDRS-1 in 1983. Of the 11 TDRS space- craft placed in service to date, eight still are operational. TDRS-M, the next spacecraft in this series, is on track to be ready for launch in late 2015.
    [Show full text]
  • Investigating High Field Gravity Using Astrophysical Techniques
    INVESTIGATING HIGH FIELD GRAVITY USING ASTROPHYSICAL TECHNIQUES Elliott D. Bloom Stanford Linear Accelerator Center Stanford University, Stanford, CA 94309 E. D. Bloom 1994 2 Table of Contents Preface 1. Introduction 2. The Physics of Compact Stellar Objects a. Schwarzschild Geometry b. The Equation of of State of Compact Stellar Objects c. The End State of Stars (i) White Dwarfs (ii) Neutron Stars (iii) Strange Stars, Q-Stars, and Black Holes (iv) Summary 3. Laboratories for Particle Astrophysics: X-Ray Stellar Binary Systems and Active Galactic Nuclei (AGN) a. Description of X-Ray Binary Systems b. Description of Active Galactic Nuclei (AGN) c. X-Ray Binary System Orbital Parameters d. Using Orbital Parameters to Determine Compact Object Masses (i) Some Leading Stellar Black Hole Candidates (ii) The Black Hole Candidate in the AGN of M87 e. Using Fast X-Ray Timing to Measure the Compact Size of Compact Stellar Objects (i) X-Ray Timing Measurements for Cyg X-1 4. X-Ray Astrophysics a. X-Ray Discriminants Black Holes vs. Neutron Stars b. Future X-Ray Missions (i) The Unconventional Stellar Aspect Experiment (USA) (ii) The X-Ray Timing Explorer (XTE) 3 5. Gamma-Ray Astrophysics a. Gamma-Ray Bursters b. Results from High-Energy Gamma-Ray Experiments (i) Space Based (mainly EGRET) (ii) Ground Based c. Future High-Energy Gamma-Ray Missions 6. Conclusions 7. Acknowledgments 8. Appendices A. Introduction to Wavelet Methods B. A List of Current Black Hole Candidates 9. References 4 Preface The purpose of these lectures is to introduce particle physicists to astrophysical techniques. These techniques can help us understand certain phenomena important to particle physics that are currently impossible to address using standard particle physics experimental techniques.
    [Show full text]
  • Appendix a TABLES of Eoss in NEUTRON STAR CRUST
    Appendix A TABLES OF EOSs IN NEUTRON STAR CRUST In this Appendix we present tables of the EOS for the ground-state matter in the neutron star crust for ρ>107 gcm−3. At lower densities, the EOS can be influenced by the presence of strong magnetic fields (Chapter 4) and by the thermal effects (Chapter 2). The analytical description of properties of atomic nuclei in neutron star crusts is given in the Appendix B, and the analytic parameterization of the EOS is presented in the Appendix C. The outer crust. Up to ρ 1011 gcm−3, the EOS in the outer crust is determined by experimental masses of neutron rich nuclei. This fact was exploited by Haensel & Pichon (1994, referred to as HP), who made maximal use of the experimental data. At higher densities, they used the semiempirical massformula of M¨oller (1992).1 The HP EOS is given in Table A.1 for the same pressure grid as in the tabulated EOS of Baym et al. (1971b, referred to as BPS), except for the last line, which corresponds to the neutron drip point. The EOS in Table A.1 is very similar to the BPS one; typical differences in density at the same pressure do not exceed a few percent. One can refine the EOS by introducing density discontinuities which accompany changes of nuclides. It can be done by inserting additional pairs of lines (ni,ρi,Pi), (ni+1,ρi+1,Pi), corresponding to the density jumps given in Table 3.1. This would complicate the integration of the equations of hydrostatic equilibrium while constructing neutron star models.
    [Show full text]
  • A Numerical Study of Solitonic Boson Stars in General Relativity
    A Numerical Study of Solitonic Boson Stars in General Relativity Philip Etter a senior thesis submitted in partial fulfillment of the requirements for the degree of Bachelor of Arts in Mathematics at Princeton University 2017 c Copyright 2017 by Philip Etter. All rights reserved. Honor Pledge I pledge my honor that this paper represents my own work in accordance with University regulations. iii Abstract In the wake of the recent detection of gravitational wave signal GW150914, we investigate whether GW150914 could have been produced by something other than a binary black hole system. Our proposed candidate is a binary system of solitonic boson stars. The choice of solitonic boson stars is due mainly to the structural properties of their ground states, as solitonic boson stars are capable of forming very compact thin-wall ground states which would likely correctly mimic the gravitational signature of the plunge/merger phase of the binary system lifecycle. On the other hand, the question of whether solitonic boson stars could also mimic the gravitational signature of the subsequent ringdown phase is still open. Since there is no hope of replicating the signature if these thin-wall ground states are not stable with respect to small perturbations, our ultimate goal is to study the stability properties of these thin-wall ground states numerically. Pursuing this goal, we have successfully developed numerical methods for both the computation of ground states of boson stars and the simulation of boson stars exposed to a small perturbation from a real scalar field. Our methods can compute the desired thin-wall ground states of solitonic boson stars, as well as produce a simulation of a perturbed ground state of a mini-boson star.
    [Show full text]